Projector and method for controlling a projector discharge lamp

Abstract

A control section relatively decreases an absolute value of a current supplied to a discharge lamp in a first period and relatively increases the absolute value in a second period, and in the second period, performs any one of a first control for supplying an alternating current to the discharge lamp, a second control for supplying, to the discharge lamp, a current in which a maximum duration of a first polarity is longer than that in the first control, and a third control for supplying, to the discharge lamp, a current in which a maximum duration of a second polarity is longer than that in the first control, and as the state of deterioration proceeds, decreases at least one of the maximum duration of the first polarity in the second control and the maximum duration of the second polarity in the third control.

Description

BACKGROUND[0001]1. Technical Field[0002]The present invention relates to a projector.[0003]2. Related Art[0004]A projector which uses a discharge lamp such as a high pressure mercury lamp or a metal halide lamp has been put into practical use. As such a projector, for example, in JP-A-2003-102030, a projector is disclosed which includes means for changing the intensity of a light source through color separation means or the like in synchronization with an image signal. However, JP-A-2009-237302 discloses that if the intensity of the light source is simply changed, there is a problem that electrode wear of a discharge lamp becomes noticeable.[0005]Further, in recent years, a projector which uses a discharge lamp such as a high pressure mercury lamp or a metal halide lamp and outputs a stereoscopic image has been put into practical use.[0006]As an example of a method of outputting the stereoscopic image, there is a method of switching and alternately outputting a right-eye image and a...

AI Technical Summary

Benefits of technology

The technical effect of the patent text is to provide a projector that can show an image without distorting the shape of the electrodes in the discharge lamp.

Problems solved by technology

However, JP-A-2009-237302 discloses that if the intensity of the light source is simply changed, there is a problem that electrode wear of a discharge lamp becomes noticeable.

Thus, in a case where the stereoscopic image is projected using the method of alternately outputting the right-eye image and the left-eye image, compared with a case where the planar image is projected in the related art, there is a problem that the image appears dark.

However, in this method, for example, there is a problem that the power consumption of the projector is increased or deterioration of peripheral parts is facilitated as the power consumption is increased.

Further, if a control is performed so that the luminance of the discharge lamp is decreased in a period when both the active shutters are closed and is increased in a period when any one of the active shutters is opened in order to cause the image to appear bright, the temperature of the electrode of the discharge lamp is decreased in the period when the luminance of the discharge lamp is decreased, and the meltability of the tip end of the electrode becomes insufficient, so that the electrode may be deformed.

If the electrode is deformed, the occurrence of flickering or the like may be caused.

In particular, in a case where the drive current of the discharge lamp is decreased as the state of deterioration of the discharge lamp proceeds, the brightness of the discharge lamp is decreased and the meltability of the tip end of the electrode becomes insufficient, and thus, the electrode is easily deformed.

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